The present invention relates to a new and improved apparatus for feeding sheet metal plates or panels or the like to a sheet shear arrangement, especially a computerized numerically controlled sheet shear arrangement.
In its more specific aspects the invention relates to a new and improved apparatus for feeding sheet metal plates or the like to an especially computerized numerically controlled sheet shear arrangement, comprising a working table arranged in front of the sheet shear arrangement and a feeding bar or beam arranged parallel to the cutting blades of the sheet shear arrangement which is reciprocatingly movable perpendicular to the cutting blades and longitudinally of the working table by means of driven pinion meshing with stationary toothed racks. The feeding bar or beam has a side facing the cutting blades where there are arranged holding elements equipped with lifting devices.
In an apparatus for feeding sheet metal plates to a sheet shear arrangement as known, for example, from German Patent Publication No. 3,010,062, clamping tongs and/or vacuum suction elements serve to grip and feed a sheet metal plate to the sheet shear arrangement. The feeding apparatus is provided with programming equipment for the numerical control thereof. On the side facing the cutting blades or cutters of the sheet sheer arrangement the clamping tongs are mounted to be vertically displaceably at a slide which is guided at two parallel sliding bars which are arranged perpendicular to the cutting blades. The slide is reciprocatingly displaced perpendicular to the cutting blades by means of two pinions driven by an associated driving unit. Each of the pinions mesh with a respective one of two stationarily arranged toothed racks arranged adjacent and parallel to the sliding bars. A lifting and rotating device containing vacuum suction elements are provided on the side of the slide which is remote from the cutting blades or cutters. A sheet metal stack placed on a lifting apparatus in front of the working table is passed over by the lifting and rotating device of the slide during operation of the feeding apparatus, in order to lift one sheet metal plate from the stack by means of the vacuum suction elements. The sheet metal plate carried by the vacuum suction elements is fed to the sheet shear arrangement and trimmed on all sides. After the last trimming cut the sheet metal plate is engaged by the clamping tongs for further processing. Up to a certain residual width sections also can be formed at a sheet metal plate which is carried by the vacuum suction elements, only the residual or remaining strip of the sheet metal plate being gripped by the clamping tongs for the further processing operation.
Disadvantages of the aforementioned state-of-the-art sheet metal plate feeding apparatus reside in the same being unsuited for processing heavy sheet metal plates, since the vacuum suction elements must take-up the entire weight of the sheet metal plate for the transport from the stack to the sheet shear arrangement. It is a further disadvantage that a sheet metal plate cannot be placed upon the working table within an overlapping time interval during which a previously taken-up sheet metal plate is being trimmed or cut. Furthermore, it is also a disadvantage in the known feeding apparatus that the same is unsuitable for conventional manual cutting operations for small cutting series or cutting of special sections or blanks.